This is why speedy engagements often fail, and why slowing things down is a good idea

Ariana Grande and Pete Davidson have reportedly called time on their relationship.
Evan Agostini/Invision/AP

There were many speedy celebrity engagements over the summer.

But rushing into a serious relationship doesn't always work out.

Research has shown couples who know each other for at least two years before getting engaged have the happiest marriages.

Sometimes, a quick whirlwind romance can work, as some people are just lucky.

Here are some of the reasons slowing things down can be beneficial in the long run.

Love lasts, infatuation is fleeting — that's what we're told. But hearing this idiom doesn't make your feelings any less intense when you're head over heels for someone.

At the beginning of a relationship, your hormones are going wild. Oxytocin and serotonin are flying around your body making you feel giddy, happy, and excitable, and every second thought you have is about when you can see that one special person again. So it's not all that surprising that some people ride the love wave and want to rush to the ultimate commitment as soon as possible.

Hollywood was rife with a string of speedy celebrity engagements over the summer. Justin Bieber and Hailey Baldwin, Ariana Grande and Pete Davidson, and Nick Jonas and Priyanka Chopra were just some of the couples who decided they wanted to get hitched after just a few weeks together.

But for Grande and Davidson, their whirlwind romance wasn't to be, and they reportedly called the wedding off this month. Russell Brand and Katy Perry, Pamela Anderson and Tommy Lee, and Katie Holmes and Tom Cruise are other couples who throughout history seemingly fell in love very quickly, only for their infatuation to fizzle out.

According to Melissa Hobley, the CMO of dating site OkCupid, speedy engagements and whirlwind romances may not work out because couples simply don't know each other well enough. Research has shown how people who have dated for at least two years before getting engaged have happier marriages, so there may not be any substitute for getting to know someone properly.

However, she added that "putting a ring on it quickly" doesn't necessarily mean you'll be unhappy.

"Studies have found that people who dated for a short time (less than 6 months) before getting engaged have a very wide range of martial happiness: some were very happy but others were very unhappy."

There's such a thing as waiting too long, too. Like in the film "The Five-Year Engagement," research has shown that the longer couples were engaged, the worse their marital satisfaction.

"So, rushing into engagement is not a great idea, but once engaged, couples should get their wedding planning started," Hobley said.

It's definitely a case-by-case basis. Sometimes people are lucky and truly do meet someone who's perfect for them, and hurrying to tie the knot isn't a mistake at all. But other times, people may realise soon after the initial buzz of "love at first sight" wears off that they are just too different.

They may also be a victim of circumstance, like with Davidson and Grande, who reportedly thought it wasn't the right time for their relationship to take off. As the saying goes: "If you have chemistry, you only need one other thing. Timing. But timing's a b---h."

Slow and steady(ish) is the winning combination

For those who get carried away at the start, things can accelerate quickly. But slower dating is a better way to get to know someone, according to the work of Sara Konrath, a social psychologist and consultant for OkCupid.

"Just like the slow food movement is a reaction to cheap and unhealthy fast food, the slow dating movement is a reaction to quick and meaningless hookups that can be made easy by dating apps," she said. "It's based on a desire for people to slow things down, get to know one another without so much pressure, and focus on high quality connection and closeness."

It can be difficult to take outside advice when you're wrapped up in the heat of love. But going all in too quickly may make the breakup all the more painful if it does eventually happen, because you've invested so much.

Here are four reasons slowing things down can help build a long-lasting, healthy relationship.

Research has shown that about a third of couples enter into sexual relationships within a month of dating, and this is associated with lower relationship quality later on compared to those who wait longer before before having sex. They simply have more time to build emotional intimacy, and work out if they really are compatible. "The rapid entry into sexual relationships, however, may cut short this process," she said. "Setting the stage for 'sliding' rather than 'deciding' to enter into cohabiting unions, and even leading to unhealthy or dissatisfying marriages."

Waiting longer helps you avoid getting attached to someone without really knowing them — meaning you could bond to someone who is completely wrong for you. "Sexual behaviors lead to the release of oxytocin and other bonding hormones, which can make people feel closeness even when it is not a good idea," said Hobley. "Slowing it down allows people to make decisions with their heart and their head."

Emotional intimacy and trust take time, she added, so allowing them to slowly build rather than forcing it means you'll have a more solid foundation to fall back on when the tough times come.

Emotionally unhealthy people, like those with unhealthy attachment styles, are more likely to rush into a relationship. This could be because they've been hurt in the past, they've been through trauma, or even if they are feeling vulnerable after the breakdown of a recent relationship. "Happier and secure people feel comfortable taking things slow and enjoying the process," Hobley said. So if you feel you're rushing into something because you're scared of being alone, or you don't feel complete without someone by your side, it might be worth working out why that is before you let someone in. Otherwise you may end up getting even more hurt because you haven't truly healed from your past.